Wood finishing method



Dec. 25, 1962 J. M. BERRY 3,070,458

woon FINISHING METHOD Filed May 14, 1958 SMOOTH,SANDED, woon SURFACE APPLY COAT}NG OF AQUEOUS FIXING AGENT DRY FIXING AGENT ON WOOD APPLY COATING OF AQUEOUTS FILLER-SEALER DRY FILLER-SEALER ON WOOD SAND WOOD COATED WITH FILLER-SEALER APPLY FINISH COATS INVENTOR. JOHN M. BERRY v MfZJA ATTORNEYS States .lohn M. Berry, Martinsville, Va., assignor to Midland Chemical Corporation, Dayton, Ohio, a corporation of Delaware Filed May 14, 1958, Ser. No. 735,239 7 Claims. (Cl. 117-72) This invention relates to a method of finishing wood particularly wood of high quality used in furniture having decorative as well as functional purposes.

In the process of invention water is employed as a primary solvent for components which stain, fill and seal to prepare the wood for a finishing protective coat and this is accomplished with a minimum of time and labor.

Water stains, such as the aniline dyes have long been considered more eflFective in the attainment of a uniform color in wood than the oil and spirit stains. Water stains, however, tend to raise the grain of the wood resulting in much labor to overcome the effect produced. Consequently water stains have been limited in their application very generally to the higher priced furniturefield.

For example, in a conventional system the wood, sanded smooth, is first sprayed with the stain; over the stain a Wash coat is applied and the wash coat is sanded; the filler is then sprayed, brushed out, padded in and finally the excess of filler is wiped off; thereafter the sealer is sprayed on, then sanded, a shade operation is elfected and the usual three coats of finishinglacquer are applied. The total time employed may be about oneman hour for a given area; generally however three and four men must be available for operations such as the brushing, padding and wiping of the filler in order that this operation 1 will be performed within appropriate time.

With the method of invention set forth herein the wash coat and consequently the sanding of the wash coat, the brushing, padding and Wiping, and the shade operation are totally eliminated. Therefore the operation is much faster, requiring only about 50 percent of the man hours of the conventional system.

Further, the woods finished in accordance with this invention have a protective and decorative surface which is Weather resistant, adherent, abrasion resistant, and

which possesses greater permanence of color than do products made by present conventional techniques.

A primary object of the present invention is to provide an improved wood finishing process which employs components having water as the principal dispersing agent for the components.

A particular object of the invention is to provide an improved wood finishing process which is economical and saving of time.

Yet another object of the invention is to provide a wood finishing process wherein, if desired, the wood may be finished in natural color rather than stained with color.

In the practice of this invention the'wood, sanded smooth, has first a fixing agent applied thereto, and this is followed by the application of a filler-sealer composition; upon hardening the film formed by the filler-sealer is sanded to remove any surface irregularities present. The wood is then ready for the application of the finishing lacquer or varnish protective coats.

The fixing agent is an aqueous solution which may have a water soluble dye dispersed therein. The function of the fixing agent is dual; first, it has a filling action for the pores of the wood without occasioning grain-raising to any substantial extent and not in any event sufiicient to require sanding before application of the filler-sealer; and second, the fixing agent provides a film over the wood, which film is homogeneous, water soluble continuous hard and amorphous; the film, when stain is not applied in the fixing agent, is substantially indistinguishable, but when color is employed the uniformity of the stained surface and the film presence is clearly discernible.

Suitably the components of the fixing agent provide the Water soluble film such that it functions as a source of hydrogen ions when wetted.

The filler-sealer composition is applied over the dried fixing agent film and wets and dissolves the film to an extent. The filler-sealer also serves a variety of purposes: first, being aqueous, it tends to dissolve the fixing agent film; secondly, it provides additional filling of the Wood pores by provision of a water dispersible filler which penetrates the aqueous fixing agent to complete filling of the wood pores; thirdly, the filler-sealer provides a sealing component which, while water dispersible, is of a particle size sulficient to inhibit any material penetration of the wood-and further the sealing component is preferably reactive with the fixing agent, or is provided to react in the presence of the fixing agent, to result in a hard amorphous transparent film through which the grain of the wood isvisible.

In the preferred practice of the invention the fixing agent comprises an aqueous solution of: (a) a carbohydrate which is water dispersible and which does not furnish aldehyde or ketonic groupings in any substantial quantity-for such would interfere with the hardening of the filler-sealer; (b) boric acid to promote osmosis and more importantly to complex with the carbohydrate; (c) an alum to combine with the boric acid and sugar in the formation of the hard, fixing-agent film and to also toughen and lessen penetration of the wood and produce in the film a source of hydrogen ions which source is later developable for combination with the liter-sealer; (d) a spreading agent to level the composition on the wood and provide for the formation of a continuous uniform filmthis spreading agent may be eliminated with open pore woods which permit leveling of the fluid film readily; and (e) a water-soluble dye to produce the desired color or tone or pigment.

Such solution should have a pH of less than about 3.5.

The filler-sealer aqueous suspension is preferably on the neutral to slightly alkaline side, the pH ranging from 7.0 up to about 8.5 and the suspension comprises pref erably:

(a) Thecarbohydrate employed in the fixing agent;

(b) An acid reactive B stage resin which polymerizes under acidic conditions to a hard, insoluble, transparent product; and

(c) A spreading agent similar to that employed in the fixing agent.

The accompanying drawing illustrates the steps of the procedure in the application of the filler-sealer. As will be noted fromthe "illustration the process is much simplified over conventional procedures.

By way of specific examples the sanded wood surface may have sprayed thereon a composition containing:

Example A tion containing: Sugar pounds Urea-formaldehyde do Mono-butyl ether of diethylene glycol (Butyl Carbitol) gallon /2 Mono-butyl ether of ethylene glycol (Butyl Cellosolve) liquid ounces Water gallons 2 /2 To form this composition the resin is first dispersed in the water, the sugar is added, followed by the monobutyl ether of diethylene glycol and mono-butyl ether of ethylene glycolall while agitating. To the milky white suspension attained water is added in sufiicient quantity to make 5 gallons.

The wood surface thus sprayed is then dried. The fillersealer film should be air dried for a short period and may be completely air dried to hardness; however, if desired, force drying for a period of 1 to 3 hours may follow an air-drying period of about /2 hour at room temperature. Air-drying'for a short period prevents any tendency of the film to blister.

A good sanding of the dried film is then eifected and the finishing coats, such as 3 coats of a nitro-cellulose lacquer are applied. Alternatively urea-alkyd varnishes or natural resin varnishes, such as Congo gum, may be applied as the finish coats.

Example B To utilize a stain there may be added to one gallon of the solution of the fixing agent of Example A, the following:

Ounces Calcocid ScarletMoO conc 5 Yellow Powder #700 1 Buffalo Black nBR, 126% /2 Spray or dip non-grain raising wood hardener.

Such will result in a non-bleeding uniform coloration when the filler-sealer has been applied and cured.

The filler-sealer composition may contain:

Pounds Sugar 1O Urea-formaldehyde 15 Water 19.8

The sugar and the resin are dispersed in the water using simple mixing equipment, and there is then added mono-butyl ether of diethylene glycol, mono-butyl ether of ethylene glycol and water sufiicient to make 5 gallons.

The application of the compositions is the same as set out under Example A.

Example D A pigmented fixing agent may contain: Titanium dioxide 2 gallons to 1 gallon of the fixing agent of Example A.

The filler-sealer may contain 2 pounds of titanium dioxide to 1 gallon of the clear filler-sealer of Example A.

In each case the titanium dioxide is dispersed in the aqueous system by grinding in a pebble mill or other suitable paint grinding equipment.

Pigmented dispersions are preferably sprayed and resuit in films having a high degree of opacity.

It is 3150 to be particularly noted that by the practice of the present invention since no wiping of the filler is necessary that drying of a wiped filler is also not necessary. Normally such drying operation requires a considerable period of time and tends to slow production operations.

This application is related to my copending applications, Serial No. 735,237, filed May 14, 1958, and entitled: Aqueous Wood Fixing Composition and Process of Fixing a Wood Surface, now abandoned, and Serial No. 735,238, filed May 14, 1958, and entiled: Aqueous Fillerealer Composition for Wood, now US. Patent No. 3,022,258, and assigned to the same assignce as the present invention.

It will be understood that this invention is susceptible to modification in order to adapt it to difierent usages and conditions and accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

What is claimed is:

1. In a wood finishing process the steps of exposing a smooth surface of the wood to an aqueous fixing agent solution containing sucrose, boric acid and an alum and which solution has the property of drying on wood to a continuous, water-soluble film, which film exhibits when wetted an acidic character, drying the fixing agent solution on the wood to form the continuous water soluble fixing agent film, applying to the continuous water soluble fixing agent film an aqueous dispersion containing sucrose and dispersed urea-formaldehyde resin which is hardenable by contact with an acid, whereby said dispersion wets and dissolves the fixing agent film to form a fluid layer on the wood surface and the wood pores are filled with sucrose, and drying the fiuid layer until the urea-formaldehyde resin is hardened.

2. In a Wood finishing process the steps of exposing a smooth surface of the wood to an aqueous fixing agent solution containing a water-soluble stain, sucrose, boric acid and an alum and which solution has the property of drying on wood to a continuous, water-soluble film, which film exhibits when wetted an acidic character, drying the fixing agent solution on the wood to form the continuous water soluble fixing agent film, applying to the continuous water soluble fixing agent film an aqueous dispersion containing sucrose and dispersed urea-formaldehyde resin which is hardenable by contact with an acid, whereby said dispersion wets and dissolves the fixing agent film to form a fluid layer on the wood surface and the wood pores are filled with sucrose, and drying the fluid layer until the urea-formaldehyde resin is hardened.

3. In a wood finishing process the steps of exposing a smooth surface of the wood to an aqueous fixing agent solution containing a dispersed pigment, sucrose, boric acid and an alum and which solution has the property of drying on wood to a continuous, water-soluble film, which film exhibits when wetted an acidic character, drying the fixing agent solution on the wood to form the continuous water soluble fixing agent film, applying to the continuous water soluble fixing agent film an aqueous dispersion containing sucrose and dispersed urea-formaldehyde resin which is hardenable by contact with an acid, whereby said dispersion wets and dissolves the fixing agent film to form a fluid layer on the wood surface and the wood pores are filled with sucrose, and drying the fluid layer until the urea-formaldehyde resin is hardened.

4. In a wood finishing process the steps of exposing a smooth surface of the wood to an aqueous fixing agent solution containing sucrose, boric acid and an alum and which solution has the property of drying on wood to a continuous, Water-soluble film, which film exhibits when wetted an acidic character, drying the fixing agent solution on the Wood to form the continuous water soluble fixing agent film, applying to the continuous water soluble fixing agent film an aqueous dispersion containing sucrose and dispersed urea-formaldehyde resin which is hardenable by contact with an acid, whereby said dispersion wets and dissolves the fixing agent film to form a fluid layer on the wood surfaceand the Wood pores are filled with sucrose, drying the fiuid layer hardened to a film, sanding the hardened film, and thereafter applying a finished coat to the film.

5. In a wood finishing process the steps of exposing a smooth surface of the wood to an aqueous fixing agent solution containing sucrose, boric acid and an alum and which solution has the property of drying on wood to a continuous, water-soluble film, which film exhibits when wetted an acidic character, drying the fixing agent solution on the wood to form the continuous water soluble fixing agent film, applying to the continuous water soluble fixing agent film an aqueous dispersion containing sucrose and dispersed urea-formaldehyde resin which is hardenable by contact with an acid, whereby said dispersion wets and dissolves the fixing agent film to form a fluid layer on the wood surface and the wood pores are filled with sucrose, drying the fiuid layer until the urea-formaldehyde resin is hardened, and maintaining a temperature of less than 110 F. during each of the drying operations.

6. In a wood finishing system the steps of exposing a smooth surface of the Wood successively to a fixing agent solution and an aqueous resin-containing dispersion, said fixing agent containing:

Sugar (cane or beet), pounds.

Boric acid, 1 pound.

Alum, 1 pound.

Mono-butyl ether of diethylene glycol (Butyl Carbitol),

/2 gallon (about 4 pounds).

Mono-butyl ether of ethylene glycol (Butyl Cellosolve),

1 quart (about 1.9 pounds).

Water, 3.3 gallons (about 27.6 pounds) (sufiicient to make 5 gallons).

said aqueous dispersion containing:

Sugar pounds 5 Urea-formaldehyde do 15 Mono-butyl ether of diethylene glycol (Butyl Carbitol) gallon /2 Mono-butyl ether of ethylene glycol (Butyl Cellosolve) liquid ounces 20 Water gallons 2 /2 drying the fixing agent prior to application of the dispersion, and drying the applied dispersion to a hard insoluble film.

7. In a wood finishing system the steps of exposing a smooth surface of the wood successively to a fixing agent solution and an aqueous resin-containing dispersion, said fixing agent containing:

said aqueous dispersion containing:

Pounds Sugar s 10 Ureaformaldehyde 15 Water 19.8

drying the fixing agent prior to application of the disper: sion, and drying the applied dispersion to a hard insoluble l i 1 References Cited in the file of this patent UNITED STATES PATENTS 2,015,806 Menger Oct. 1, 1935 2,271,212 Tenger Jan. 27, 1942 2,817,620 Golick et a1 Dec. 24, 1957 FOREIGN PATENTS 688,198 Great Britain Mar. 4, 1953} 

1. IN A WOOD FINISHING PROCESS THE STEPS OF EXPOSING A SMOOTH SURFACE OD THE WOOD TO AN AQUEOUS FIXING AGENT SOLUTION CONTAINING SUCROSE, BORIC ACID AND AN ALUM AND WHICH SOLUTION HAS THE PROPERTY OF DRYING ON WOOD TO A CONTINOUS, WATER-SOLUBLE FILM, WHICH FILM EXHIBITS WHEN WETTED AN ACIDIC CHARACTER, DRYING THE FIXING AGENT SOLUTION ON THE WOOD TO FORM THE CONTINUOUS WATER SOLUBLE FIXING AGENT FILM, APPLYING TO THE CONTINUOUS WATER SOLUBLE FIXING AGENT FILM AN AQUEOUS DISPERSION CONTAINING SUROSE AND DISPERSED UREA-FORMALDHYDE RESIN WHICH IS HARDEN- 